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1.
Stone tools characteristic of the Clovis culture have been found in direct association with bones of the American mastodon at Kimmswick, Missouri. The vertebrate fauna from Clovis components suggests a deciduous woodland and meadow habitat. Such an environmental reconstruction provides a new perspective for Clovis adaptations and the ecological tolerances of Mammut americanum. 相似文献
2.
Bryan AL Casamiquela RM Cruxent JM Gruhn R Ochsenius C 《Science (New York, N.Y.)》1978,200(4347):1275-1277
Excavation at Taima-taima in 1976 recovered artifacts of the El Jobo complex in direct association with the butchered remains of a juvenile mastodon. Radiocarbon dates on associated wood twigs indicate a minimum age of 13,000 years before the present for the mastodon kill, a dating significantly older than that of the Clovis complex in North America. The El Jobo complex must have evolved independently in northern South America. 相似文献
3.
Archeological excavations at Murray Springs, Cochise County, Arizona, in July 1967 uncovered a unique bone tool in the Clovis occupation level and in association with bones of a mammoth. The tool may be a wrench for straightening shafts of spears; if so, shaft diameters ranging from 14 to 17 millimeters were most likely used in hafting Clovis projectile points. 相似文献
4.
DL Jenkins LG Davis TW Stafford PF Campos B Hockett GT Jones LS Cummings C Yost TJ Connolly RM Yohe SC Gibbons M Raghavan M Rasmussen JL Paijmans M Hofreiter BM Kemp JL Barta C Monroe MT Gilbert E Willerslev 《Science (New York, N.Y.)》2012,337(6091):223-228
The Paisley Caves in Oregon record the oldest directly dated human remains (DNA) in the Western Hemisphere. More than 100 high-precision radiocarbon dates show that deposits containing artifacts and coprolites ranging in age from 12,450 to 2295 (14)C years ago are well stratified. Western Stemmed projectile points were recovered in deposits dated to 11,070 to 11,340 (14)C years ago, a time contemporaneous with or preceding the Clovis technology. There is no evidence of diagnostic Clovis technology at the site. These two distinct technologies were parallel developments, not the product of a unilinear technological evolution. "Blind testing" analysis of coprolites by an independent laboratory confirms the presence of human DNA in specimens of pre-Clovis age. The colonization of the Americas involved multiple technologically divergent, and possibly genetically divergent, founding groups. 相似文献
5.
Waters MR Forman SL Jennings TA Nordt LC Driese SG Feinberg JM Keene JL Halligan J Lindquist A Pierson J Hallmark CT Collins MB Wiederhold JE 《Science (New York, N.Y.)》2011,331(6024):1599-1603
Compelling archaeological evidence of an occupation older than Clovis (~12.8 to 13.1 thousand years ago) in North America is present at only a few sites, and the stone tool assemblages from these sites are small and varied. The Debra L. Friedkin site, Texas, contains an assemblage of 15,528 artifacts that define the Buttermilk Creek Complex, which stratigraphically underlies a Clovis assemblage and dates between ~13.2 and 15.5 thousand years ago. The Buttermilk Creek Complex confirms the emerging view that people occupied the Americas before Clovis and provides a large artifact assemblage to explore Clovis origins. 相似文献
6.
Formal and functional analyses of bone artifacts from a Clovis burial in southwestern Montana suggest that they were constructed to serve as (detachable or nondetachable) foreshafts for attaching fluted projectile points to lance shafts. 相似文献
7.
The Clovis complex is considered to be the oldest unequivocal evidence of humans in the Americas, dating between 11,500 and 10,900 radiocarbon years before the present (14C yr B.P.). Adjusted 14C dates and a reevaluation of the existing Clovis date record revise the Clovis time range to 11,050 to 10,800 14C yr B.P. In as few as 200 calendar years, Clovis technology originated and spread throughout North America. The revised age range for Clovis overlaps non-Clovis sites in North and South America. This and other evidence imply that humans already lived in the Americas before Clovis. 相似文献
8.
Excavations at the Mesa site in arctic Alaska provide evidence for a Paleoindian occupation of Beringia, the region adjacent to the Bering Strait. Eleven carbon-14 dates on hearths associated with Paleoindian projectile points place humans at the site between 9,730 and 11,660 radiocarbon years before present (years B.P.). The presence of Paleoindians in Beringia at these times challenges the notion that Paleoindian cultures arose exclusively in mid-continental North America. The age span of Paleoindians at the Mesa site overlaps with dates from two other cultural complexes in interior Alaska. A hiatus in the record of human occupation occurs between 10,300 and 11,000 years B.P. Late Glacial climatic fluctuations may have made northern Alaska temporarily unfavorable for humans and spurred their southward dispersal. 相似文献
9.
Organ CL Schweitzer MH Zheng W Freimark LM Cantley LC Asara JM 《Science (New York, N.Y.)》2008,320(5875):499
We report a molecular phylogeny for a nonavian dinosaur, extending our knowledge of trait evolution within nonavian dinosaurs into the macromolecular level of biological organization. Fragments of collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a variety of phylogenetic methods. Despite missing sequence data, the mastodon groups with elephant and the T. rex groups with birds, consistent with predictions based on genetic and morphological data for mastodon and on morphological data for T. rex. Our findings suggest that molecular data from long-extinct organisms may have the potential for resolving relationships at critical areas in the vertebrate evolutionary tree that have, so far, been phylogenetically intractable. 相似文献
10.
Buckley M Walker A Ho SY Yang Y Smith C Ashton P Oates JT Cappellini E Koon H Penkman K Elsworth B Ashford D Solazzo C Andrews P Strahler J Shapiro B Ostrom P Gandhi H Miller W Raney B Zylber MI Gilbert MT Prigodich RV Ryan M Rijsdijk KF Janoo A Collins MJ 《Science (New York, N.Y.)》2008,319(5859):33; author reply 33
We used authentication tests developed for ancient DNA to evaluate claims by Asara et al. (Reports, 13 April 2007, p. 280) of collagen peptide sequences recovered from mastodon and Tyrannosaurus rex fossils. Although the mastodon samples pass these tests, absence of amino acid composition data, lack of evidence for peptide deamidation, and association of alpha1(I) collagen sequences with amphibians rather than birds suggest that T. rex does not. 相似文献
11.
《（《农业科学与技术》）编辑部》2015,(12)
Chinese pangolin(Manis pentadactyla) has important value in Chinese medicine,economy and ecology.At present,Chinese pangolin is about to go extinct due to over hunting and habitat destruction,which has caused a dramatic decline in the wild population.Breeding Chinese pangolin in captivity is very difficult and has not succeeded yet.This paper is to review the wild population,habitat,foraging,activity rhythm,breeding and physiology of Chinese pangolin.It provides theoretical basis of ecology and biology for the protection and artificial domestication of Chinese pangolin.Meanwhile,given the demands of protection,future research directions are suggested. 相似文献
12.
Gilbert MT Jenkins DL Götherstrom A Naveran N Sanchez JJ Hofreiter M Thomsen PF Binladen J Higham TF Yohe RM Parr R Cummings LS Willerslev E 《Science (New York, N.Y.)》2008,320(5877):786-789
The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America at about 11,000 to 10,800 radiocarbon years before the present (14C years B.P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point Caves, in south-central Oregon, by 12,300 14C years B.P., through the recovery of human mitochondrial DNA (mtDNA) from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are >1000 14C years earlier than currently accepted dates for the Clovis complex. 相似文献
13.
Erlandson JM Rick TC Braje TJ Casperson M Culleton B Fulfrost B Garcia T Guthrie DA Jew N Kennett DJ Moss ML Reeder L Skinner C Watts J Willis L 《Science (New York, N.Y.)》2011,331(6021):1181-1185
Three archaeological sites on California's Channel Islands show that Paleoindians relied heavily on marine resources. The Paleocoastal sites, dated between ~12,200 and 11,200 years ago, contain numerous stemmed projectile points and crescents associated with a variety of marine and aquatic faunal remains. At site CA-SRI-512 on Santa Rosa Island, Paleocoastal peoples used such tools to capture geese, cormorants, and other birds, along with marine mammals and finfish. At Cardwell Bluffs on San Miguel Island, Paleocoastal peoples collected local chert cobbles, worked them into bifaces and projectile points, and discarded thousands of marine shells. With bifacial technologies similar to those seen in Western Pluvial Lakes Tradition assemblages of western North America, the sites provide evidence for seafaring and island colonization by Paleoindians with a diversified maritime economy. 相似文献
14.
Montané J 《Science (New York, N.Y.)》1968,161(3846):1137-1138
Bone and stone tools associated with extinct fauna (horse and mastodon) place man's occupation in central Chile at 11,380 +/- 320 years ago. 相似文献
15.
Heusser CJ 《Science (New York, N.Y.)》1983,219(4591):1429-1432
Pollen of southern beech and podocarp at Laguna de Tagua Tagua during the late Pleistocene indicates that cooler and more humid intervals were a feature of Ice Age climate at this subtropical latitude in Chile. The influence of the southern westerlies may have been greater at this time, and the effect of the Pacific anticyclone was apparently weakened. The climate today, wet in winter and dry in summer, supports broad sclerophyll vegetation that developed during the Holocene with the arrival of paleo-Indians and the extinction of mastodon and horse. 相似文献
16.
The Ushki Paleolithic sites of Kamchatka, Russia, have long been thought to contain information critical to the peopling of the Americas, especially the origins of Clovis. New radiocarbon dates indicate that human occupation of Ushki began only 13,000 calendar years ago-nearly 4000 years later than previously thought. Although biface industries were widespread across Beringia contemporaneous to the time of Clovis in western North America, these data suggest that late-glacial Siberians did not spread into Beringia until the end of the Pleistocene, perhaps too recently to have been ancestral to proposed pre-Clovis populations in the Americas. 相似文献
17.
Haynes G Anderson DG Ferring CR Fiedel SJ Grayson DK Haynes CV Holliday VT Huckell BB Kornfeld M Meltzer DJ Morrow J Surovell T Waguespack NM Wigand P Yohe RM 《Science (New York, N.Y.)》2007,317(5836):320; author reply 320
Waters and Stafford (Reports, 23 February 2007, p. 1122) provided useful information about the age of some Clovis sites but have not definitively established the temporal span of this cultural complex in the Americas. Only a continuing program of radiometric dating and careful stratigraphic correlations can address the lingering ambiguity about the emergence and spread of Clovis culture. 相似文献
18.
Organic remains, especially dung, of extinct ground sloths provide ideal material for radiocarbon dating. Rampart Cave, Arizona, revealed periodic occupation at intervals by the Shasta ground sloth from before 40,000 years ago until 11,000 years ago. Dates from other caves in the arid Southwest indicate that the Shasta ground sloth disappeared at very soon after the time of Clovis big game hunters. Ground sloth remains in South America are slightly younger. The timing of ground sloth extinction is in accord with the model of explosive overkill. 相似文献
19.
Frison GC 《Science (New York, N.Y.)》1976,194(4266):728-730
Stacked mammoth bones at the Colby site in northern Wyoming reflect human cultural activity that is believed to have been peripheral to the butchering and processing of the animals. A projectile point found beneath the first bones placed in the pile leaves no doubt of human involvement in the stacking of the bones, but the significance of this kind of cultural activity is open to several interpretations. 相似文献
20.
Asara JM Schweitzer MH Freimark LM Phillips M Cantley LC 《Science (New York, N.Y.)》2007,316(5822):280-285
Fossilized bones from extinct taxa harbor the potential for obtaining protein or DNA sequences that could reveal evolutionary links to extant species. We used mass spectrometry to obtain protein sequences from bones of a 160,000- to 600,000-year-old extinct mastodon (Mammut americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The presence of T. rex sequences indicates that their peptide bonds were remarkably stable. Mass spectrometry can thus be used to determine unique sequences from ancient organisms from peptide fragmentation patterns, a valuable tool to study the evolution and adaptation of ancient taxa from which genomic sequences are unlikely to be obtained. 相似文献